From patchwork Mon Nov 27 15:55:21 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Fabio M. De Francesco" X-Patchwork-Id: 170258 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:ce62:0:b0:403:3b70:6f57 with SMTP id o2csp3241749vqx; Mon, 27 Nov 2023 08:02:18 -0800 (PST) X-Google-Smtp-Source: AGHT+IEmaJ7GQDGt/HAAaML1j84VF/XzYl93FppOkL+PqwRKtzQe4T7g+FjFnrV8ar3qkoGTdiaQ X-Received: by 2002:a25:2d24:0:b0:d9a:b843:89af with SMTP id t36-20020a252d24000000b00d9ab84389afmr9739304ybt.38.1701100937669; Mon, 27 Nov 2023 08:02:17 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1701100937; cv=none; d=google.com; s=arc-20160816; b=e5Jhl8OLhRaBuRizxtSozbvrVy78gWD5SNThXf6ZOpLInRpWUiRm56rlP4AZwyja2+ oR6j4k7JaoU74TaCn7M+UyOgif5lm+pzw3L1DmWhM4kvJ4h/o5KMRdOQ9PWvZDzD9/4/ ID94+Y+6oTkhy0WCBtvRZNR74lbJKDVl5Bfjmfpcz3LY+miQfiomEv0rF0al4J+gtRc4 vI0pVCstbViCGcFx3HoOK2cl8W9xGBKrEhix+DUc+XkPv/sSXXSDvhr3euPaxW73eIZ6 vm6s1eT4NXcQYbSav0XVBCO8RmmnsjNknqOvlPKBdJw1kCfUJRhFPenStFj60x2ytBVx 8eyg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :message-id:date:subject:cc:to:from:dkim-signature; bh=tcGhs2hoVHaaatwgwIiyxHDFchVQg3ztRr/NJCGcRT0=; fh=INILcbFGjlr87vj9GTLv48fWFY5YA+Pa3axcVbGSz/Q=; b=gTzjMSbnT6guQb2sF4J0jki7EAYwBtBD7MEYA8CufuHGGLSNWVjG3Ecimw0wdtwb9y kFzPkcKRVw5yd2YcByNIZpHhaCwJE+/96ZF9Bjieljv2vtlVV8phixQ81ivRCHTrAfsN h5uAvveVuYf51kPra+DYCoEE0kRSxh4Y/lZItqyrwjDfjq8zG+z+AcA+Ro4egFZJsS+n bYxll4puTWHBeOv6Qeik6upBvozMLBAacyhQW4l9lq6gBFQl+5dKSWZEMyLmZ1C9/pjZ xXp/Nz4cFw/7CWCvfx13jfwbiT9wcdQQaItyiseTmDX5yES53I29nfYq/XW5O3siFU++ Oc8w== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@intel.com header.s=Intel header.b=fSYpJ9WH; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.37 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: from snail.vger.email (snail.vger.email. [23.128.96.37]) by mx.google.com with ESMTPS id o10-20020a25410a000000b00d9a46928ed7si6553223yba.602.2023.11.27.08.02.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 27 Nov 2023 08:02:17 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.37 as permitted sender) client-ip=23.128.96.37; Authentication-Results: mx.google.com; dkim=pass header.i=@intel.com header.s=Intel header.b=fSYpJ9WH; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.37 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: from out1.vger.email (depot.vger.email [IPv6:2620:137:e000::3:0]) by snail.vger.email (Postfix) with ESMTP id D6F268072151; Mon, 27 Nov 2023 08:01:49 -0800 (PST) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.11 at snail.vger.email Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234270AbjK0QBi (ORCPT + 99 others); Mon, 27 Nov 2023 11:01:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38496 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233859AbjK0QBh (ORCPT ); Mon, 27 Nov 2023 11:01:37 -0500 Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.120]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B84FBB4 for ; Mon, 27 Nov 2023 08:01:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1701100903; x=1732636903; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=yv7LtoQLd141WmTkO/xz5VJsS/q7Vvm2oGrcJcBIg/8=; b=fSYpJ9WH6pRxgBR9eOgwb1PJOOeNRBab7/BWFnCXQLLKijO97k95EDoN hC5yGfqf/SfXIOMnqN0waUP/o8PyKYe6M4+APhkeEbbNh/kCYY1kOKyWl UfsuJe/DPgB1LLJ1neAIYZKMpRglxIa+Rp0fC1flAfaOx0rPgZBzY3QPU A0pVHHdSNYuasAzcUoLkv9r5y11lg0yrFcxis826X9Vq1/NZR2tz/sN3V ulUgX3lSsHbmEtA9WVYJdszfY6zrcKzqgqo0PHLGy/obw6w+/BPj83zit mwXIUUqcpHeT8AHphRLLLo4N7x9X0ycEpikqMFnV+81W82ycnbdlKbOFo w==; X-IronPort-AV: E=McAfee;i="6600,9927,10907"; a="391609974" X-IronPort-AV: E=Sophos;i="6.04,231,1695711600"; d="scan'208";a="391609974" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Nov 2023 08:01:43 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10907"; a="1099823579" X-IronPort-AV: E=Sophos;i="6.04,231,1695711600"; d="scan'208";a="1099823579" Received: from fdefranc-mobl3.ger.corp.intel.com (HELO fdefranc-mobl3.Hitronhub.home) ([10.213.15.40]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Nov 2023 08:01:40 -0800 From: "Fabio M. De Francesco" To: Seth Jennings , Dan Streetman , Vitaly Wool , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: "Fabio M. De Francesco" , Ira Weiny Subject: [PATCH] mm/zswap: Replace kmap_atomic() with kmap_local_page() Date: Mon, 27 Nov 2023 16:55:21 +0100 Message-ID: <20231127160058.586446-1-fabio.maria.de.francesco@linux.intel.com> X-Mailer: git-send-email 2.42.0 MIME-Version: 1.0 X-Spam-Status: No, score=0.5 required=5.0 tests=AC_FROM_MANY_DOTS,BAYES_00, DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_EF, RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_NONE,T_SCC_BODY_TEXT_LINE autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (snail.vger.email [0.0.0.0]); Mon, 27 Nov 2023 08:01:50 -0800 (PST) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1783732648597202724 X-GMAIL-MSGID: 1783733616348952168 kmap_atomic() has been deprecated in favor of kmap_local_page(). Therefore, replace kmap_atomic() with kmap_local_page() in zswap.c. kmap_atomic() is implemented like a kmap_local_page() which also disables page-faults and preemption (the latter only in !PREEMPT_RT kernels). The kernel virtual addresses returned by these two API are only valid in the context of the callers (i.e., they cannot be handed to other threads). With kmap_local_page() the mappings are per thread and CPU local like in kmap_atomic(); however, they can handle page-faults and can be called from any context (including interrupts). The tasks that call kmap_local_page() can be preempted and, when they are scheduled to run again, the kernel virtual addresses are restored and are still valid. In mm/zswap.c, the blocks of code between the mappings and un-mappings do not depend on the above-mentioned side effects of kmap_atomic(), so that the mere replacements of the old API with the new one is all that is required (i.e., there is no need to explicitly call pagefault_disable() and/or preempt_disable()). Cc: Ira Weiny Signed-off-by: Fabio M. De Francesco Reviewed-by: Nhat Pham Acked-by: Chris Li (Google) --- mm/zswap.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/mm/zswap.c b/mm/zswap.c index 74411dfdad92..699c6ee11222 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -1267,16 +1267,16 @@ bool zswap_store(struct folio *folio) } if (zswap_same_filled_pages_enabled) { - src = kmap_atomic(page); + src = kmap_local_page(page); if (zswap_is_page_same_filled(src, &value)) { - kunmap_atomic(src); + kunmap_local(src); entry->swpentry = swp_entry(type, offset); entry->length = 0; entry->value = value; atomic_inc(&zswap_same_filled_pages); goto insert_entry; } - kunmap_atomic(src); + kunmap_local(src); } if (!zswap_non_same_filled_pages_enabled) @@ -1422,9 +1422,9 @@ bool zswap_load(struct folio *folio) spin_unlock(&tree->lock); if (!entry->length) { - dst = kmap_atomic(page); + dst = kmap_local_page(page); zswap_fill_page(dst, entry->value); - kunmap_atomic(dst); + kunmap_local(dst); ret = true; goto stats; }